It is known to identify the geographical position of mobile devices, such as cellular telephones, PDAs etc., by the aid of so-called triangulation. The approximate localization of the mobile devices is defined via the sensing of signal strength of the radio of at least three radio towers, i.e. base stations, of the network of the mobile device. Other positioning methods, such as Cell ID, CGI/TA, E-CGI and A-GPS are also available.
It is further known to identify the position of lost or stolen objects by the aid of GPS positioning means. Objects may hereby be equipped with preferably concealed GPS trackers, i.e. GPS receivers, which are actuatable by a center station or a user via radio communication to collect positioning data for the object from GPS satellites. Such tracker is known from for instance GB2483459 A or GB2484273 A. A drawback with these types of trackers is that they require a costly mobile phone subscription and a configuration of for instance a GSM modem and GPS receiver devices. Said devices are highly energy consuming and therefore need to be equipped with relatively bulky batteries which requires constant charging and operator discipline in terms of shutting the GPS tracker on and off to work as intended. The increased cost, size, weight and bulkiness further reduces the GPS trackers usability for certain applications wherein such parameters are preferably kept low, e.g. to track stolen bicycles, vehicles etc. For instance, it is generally not feasible to track objects of relatively low cost compared to the GPS trackers themselves, and a single user may not be able to afford to equip all objects he desires with expensive GPS trackers. Some objects, such as for instance bicycles or motorbikes are stolen in large volumes, generating high costs not only for the owners but further to the insurance companies. A further drawback is that a stolen or lost object to be tracked by using a GPS tracker may be positioned such that their ability to receive either GPS signals or signals via the mobile network is highly reduced, whereby their tracking ability is incapacitated.
There is a constant desire to provide improved and cheaper methods and devices for location devices, in particular lost devices.